Fabrication of PVDF/BaTiO3/NiO nanocomposite film as a separator for supercapacitors

The PVDF/BaTiO3/NiO nanocomposite films of similar to 50 mu m thickness are prepared via solution mixing method. The SEM images confirm the well incorporation of filler nanoparticles in the PVDF matrix with a highly porous mesh like structure. The alpha ->beta phase transition in PVDF is observed by FTIR spectroscopic analysis. The dielectric constant of the proposed separator film is found to be similar to 24, which is much higher than the micro-porous Celgard Ez 2090 (dielectric constant similar to 2.2 at 60 kHz) and previously reported separators. A well maintained quasi rectangular shape of CV curves is observed at different scan rate, which offer the excellent capacitive properties of the PVDF/BaTiO3/NiO nanocomposite separator film. The bulk electrolyte resistance (R-be) for the PVDF/BaTiO3/NiO separator film is found to be 0.6 Omega, which is much lower than the bulk electrolyte resistance for commercially available non-porous Celgard T 2500 (88.2 Omega) and micro - porous Celgard Ez 2090 (47.1 Omega). Also, the ionic conductivity (sigma) for the separator film is found 19.8 mS cm(-1), which is higher than commercially available Cellulose (10 mS cm(-1)) and non-porous Celgard (TM) 2500 (4 mS cm(-1)) and previously reported separators. The fabricated PVDF/BaTiO3/NiO nanocomposite films are proposed to be used as a separator in supercapacitors.